Systems for packaging soft drinks in bottles or cans ordinarily omit a pasteurizing station. The stored beverage syrup conventionally possesses a sugar concentration of at least about 32.degree. Baume; and a product of this elevated sugar content will not support microbiological growth. In practice, the beverage syrup is not diluted to a level where contaminant organisms might proliferate until immediately prior to carbonation and filling in the selected packages. Hence, the need for pasteurization has not existed heretofore.
In circumstances, such as may obtain in certain foreign countries for example, where the demand for carbonated drinks and the like is only of very recent origin and experienced packaging personnel are generally unavailable, and where sugar supplies are frequently of variable quality, pasteurization has proved to be a worthwhile precaution. However, heating finished soft drink products to pasteurization temperature can risk the ultimate quality of the beverage as a result of oxidizing the flavor essences or darkening because of sugar carmelization.
Prior art pasteurizing schemes for soft drinks have commonly employed means providing return circulation of quantities of the pasteurized beverage to the fresh product inlet upon those occasions when forward flow is interrupted as a consequence of intermittent demand at the filler, or otherwise. This type of flow control has been found to aggravate color and flavor problems and, depending upon the point at which the pasteurized product is fed back into the system, to introduce a possible source of microbiological contamination or at least product dilution.